1. Technical Field
This disclosure relates to RF power transistors, and more particularly to power transistor packages.
2. Discussion of Related Art
Conventional high frequency power transistor packages use of a variety of mechanical components to provide RF signal stability and integrity.
For example, U.S. Pat. No. 3,555,375 entitled High Frequency Power Transistor Having Crossing Input and Output Leads describes a technique in which compensation for stray inductive feedback coupling is achieved by crossing input and output leads. Specifically, a high frequency transistor is described having input, output, and common leads. In order to reduce the unwanted feedback effect of a stray series inductance in the common lead, the output leads are arranged so as to cross one another in such close proximity as to inductively couple them together, thereby providing a feedback opposite to that of the stray inductance in order to compensate for the stray inductance.
FIGS. 1-3 show an example of a prior art RF package in which a flanged base has arranged thereon various circuit and mechanical components such as a lead frame, a MOSFET die, source, drain, and gate leads, wire bonds, and so forth. The various parts and interconnects are distinct from the substrate and generally distinct from each other. In other words, the parts and interconnects are manufactured separately and are later mechanically assembled to form the package. While the arrangement of such components can improve signal stability and integrity to some degree, producing such packages is costly. Moreover, frequency stability and conductivity of the prior art parts is not necessarily optimal.
The mechanical construction and assembly of the separate components of the package result in higher manufacturing and labor costs, which is of critical importance when producing the packages in high quantities. Moreover, lower electrical conductivity of the parts themselves inhibits the performance of the circuit components, leads, and other electrical parts associated with the package. It would be desirable to have a sintered, monolithic package having circuit features and electrical components integrated thereon to reduce the cost associated with producing the packages, and to enhance operational characteristics and capabilities. Accordingly, a need remains for an improved RF package and method for producing the same.